Life Changing: SHORTLISTED FOR THE WAINWRIGHT PRIZE FOR WRITING ON GLOBAL CONSERVATION

By Helen Pilcher

SHORTLISTED FOR THE WAINWRIGHT PRIZE FOR WRITING ON GLOBAL CONSERVATION

'Pilcher is both very funny and very, very clever.' Gillian Burke

'Richly entertaining throughout.' Sunday Times

For the last three billion years or so, life on Earth was shaped by natural forces. Evolution tended to happen slowly, with species crafted across millennia. Then, a few hundred thousand years ago, along came a bolshie, big-brained, bipedal primate we now call Homo sapiens, and with that, the Earth's natural history came to an abrupt end. We are now living through the post-natural phase, where humans have become the leading force shaping evolution.

This thought-provoking book considers the many ways that we've altered the DNA of living things and changed the fate of life on earth. We have carved chihuahuas from wolves and fancy chickens from jungle fowl. We've added spider genes to goats and coral genes to tropical fish. It's possible to buy genetically-modified pets, eat genetically-modified fish and watch cloned ponies thunder up and down the polo field.

Now, as our global dominance grows, our influence extends far beyond these species. As we warm our world and radically reshape the biosphere, we affect the evolution of all living things, near and far, from the emergence of novel hybrids such as the pizzly bear, to the entirely new strains of animals and plants that are evolving at breakneck speed to cope with their altered environment.

In Life Changing, Helen introduces us to these post-natural creations and talks to the scientists who create, study and tend to them. At a time when the future of so many species is uncertain, we meet some of the conservationists seeking to steer evolution onto firmer footings with novel methods like the 'spermcopter', coral IVF and plans to release wild elephants into Denmark. Helen explores the changing relationship between humans and the natural world, and reveals how, with evidence-based thinking, humans can help life change for the better.

• Language: English
• Publisher: Bloomsbury Publishing
• Release date: Feb 6, 2020
• ISBN: 9781472956736

Helen Pilcher

Helen Pilcher is a tea-drinking, biscuit-nibbling science and comedy writer. She has a PhD in Cell Biology from London's Institute of Psychiatry. A former reporter for Nature, she now specializes in biology, medicine and quirky off-the-wall science, and writes for outlets including New Scientist and BBC Focus. Unusually for a self-proclaimed geek, Helen also used to be a stand-up comedian before the arrival of children meant she couldn't physically stay awake past 9pm. She now gigs from time to time, and lives in rural Warwickshire with her husband, three kids and besotted dog. @HelenPilcher1

Book preview

A NOTE ON THE AUTHOR

Helen Pilcher is a tea-drinking, biscuit-nibbling science and comedy writer with a PhD in Cell Biology. A former reporter for Nature magazine, she now specializes in biology, medicine and quirky, off-the-wall science, and writes for outlets including the Guardian, New Scientist and BBC Wildlife.

Helen’s previous book for Bloomsbury Sigma, Bring Back the King, was Radio 2 ‘Fact not Fiction’ book of the week; it was described by comedian Sara Pascoe as ‘science at its funniest’.

@HelenPilcher1

Also available in the Bloomsbury Sigma series:

Sex on Earth by Jules Howard

Spirals in Time by Helen Scales

A is for Arsenic by Kathryn Harkup

Suspicious Minds by Rob Brotherton

Herding Hemingway’s Cats by Kat Arney

The Tyrannosaur Chronicles by David Hone

Soccermatics by David Sumpter

Big Data by Timandra Harkness

Goldilocks and the Water Bears by Louisa Preston

Science and the City by Laurie Winkless

Built on Bones by Brenna Hassett

The Planet Factory by Elizabeth Tasker

Catching Stardust by Natalie Starkey

Seeds of Science by Mark Lynas

Eye of the Shoal by Helen Scales

Nodding Off by Alice Gregory

The Science of Sin by Jack Lewis

The Edge of Memory by Patrick Nunn

Turned On by Kate Devlin

Borrowed Time by Sue Armstrong

The Vinyl Frontier by Jonathan Scott

Clearing the Air by Tim Smedley

Superheavy by Kit Chapman

The Contact Paradox by Keith Cooper

Life Changing by Helen Pilcher

Sway by Pragya Agarwal

Bad News by Rob Brotherton

Kindred by Rebecca Wragg Sykes

Mirror Thinking by Fiona Murden

Our Only Home by His Holiness The Dalai Lama

First Light by Emma Chapman

Ouch! by Margee Kerr & Linda Rodriguez McRobbie

For Amy, Jess, Sam, Joe, Baba and Higgs the Genetically Modified Wolf

… to the moon and back …

and for my Dad

… who gave me my love of wild things.

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Contents

Introduction

Chapter 1: The Wolf that Rolled Over

Chapter 2: Strategic Moos and Golden Gnus

Chapter 3: Super Salmon and Spider-Goats

Chapter 4: Game of Clones

Chapter 5: Screwworms and Suicide Possums

Chapter 6: The Age of the Chicken

Chapter 7: Sea-Monkeys and Pizzly Bears

Chapter 8: Darwin’s Moth

Chapter 9: Resilient Reefs

Chapter 10: Love Island

Chapter 11 Pigs and Purple Emperors

Chapter 12: The New Ark

Additional Reading

Acknowledgements

Index

Plates

Introduction                                               

4913 Penn Avenue, Pittsburgh, Pennsylvania

Four doors down from a gluten-free bakery, two doors up from a Vietnamese takeaway, is one of the world’s most unusual museums. Its outside is elegantly under­stated. There are no ornate pillars or sweeping staircases. Instead, the façade is a muted, minimalist chequerboard fashioned from glass and steel. At a casual glance, it looks more like a trendy boutique than it does a centre for learning, yet Pittsburgh has a hidden gem squirrelled away in this bustling business street. One online review describes the museum as ‘wonderfully weird’. Another says, ‘there is nothing like it in the world’. And they’re right. Welcome to the Center for PostNatural History.

The museum’s ambassador is Freckles, a milky-coloured goat that greets the visitors when they arrive. An ‘ex’-ungulate, she’s stuffed and mounted, portraying a jaunty demeanour that borders on the mischievous. Pert ears are cocked forwards. Olive eyes protrude from a long face and her mouth is turned upwards into the semblance of a smile. Although she looks ordinary from the outside, on the inside she is anything but. Her DNA is part goat, part spider. She doesn’t have eight legs and has never spun a web, but when she was alive she did have superpowers. Freckles used to make spider proteins in her milk. She was donated to the museum by the scientists who deliberately modified her DNA. ‘She’s there as a conversation starter,’ says the museum’s director, Richard Pell. ‘She’s the first thing that you see when you walk in the door.’

Spend time at the museum and you’ll find it is home to an impressive range of equally idiosyncratic oddities. There are pressed leaves from genetically modified plants, the grimacing skull of a pug and a stuffed salmon that contains the DNA of not one but three different species. There’s a fluffy chicken with extra toes, a weird hybrid brine shrimp and the testicles of a cat called Jimmy Cat Carter. If Tim Burton made natural history museums, this is how they would be.

None of these exhibits would be found in a classic natural history museum. ‘They have a blind spot for things like this,’ says Richard. Conventional natural history museums are full of dinosaurs, glass-eyed tigers and stuffed wild birds. They’re designed to showcase the natural world, but Richard’s exhibits don’t belong there because they’re not perceived as natural. They’re not ‘unnatural’ because they are carved from the same biological building blocks as all other living things, but they’re not quite ‘natural’ either because they didn’t evolve into their current incarnations on their own. Instead, every single one has been deliberately created by humans. ‘They are all living things that have been intentionally altered in ways that are heritable and that change their evolutionary trajectory,’ says Richard. So he calls his specimens ‘post-natural’ to reflect the fact that they were created after the arrival and interference of humans.

This is a book about the Earth’s post-natural history. It’s about the relationship that exists between humans and other species, and how this has changed over time. From humble beginnings in the cradle of Africa, humans have risen to become a global superpower. Along the way, we invented technology that lets us shape the behaviour and biology of living things. We used this new power to redesign animals, plants and other organisms, and derailed their evolutionary journeys onto a new post-natural path.

Domestic species, such as dogs, cattle, sheep and pigs are all part of this story. Now we live in a world where cloned ponies play in polo tournaments, cattle are being engineered to resist disease and pigs are being modified to grow human transplant organs. The salmon with the extra DNA is a new super speedy-growing variety, while the chicken with the extra digit is one of a baffling array of domestic birds that have been variously produced for their meat, eggs, size, colour and pure novelty value. Extinct creatures are being brought back to life. As Freckles demonstrates, living animals are being modified to produce new materials and medicines. Ranchers are selectively breeding weird-coloured wild animals for paying punters to shoot, people can now pay to have their pet dog or cat cloned, and in the US, it’s possible to buy tropical fish with added jellyfish genes that make them dayglow colours. Meanwhile, Jimmy Cat Carter’s lonely gonads serve to remind us that while humans have achieved new levels of control over the future of life, we also influence the future of death. ‘Humans have acquired many strategies to prevent life from reproducing,’ says Richard. Castration is one way, as Jimmy Cat Carter found to his cost, but now researchers are developing methods that could drive entire species to extinction.

All these examples are products of intentional design, but as our global dominance reaches new heights, our influence extends far beyond these lifeforms. As we raze forests, pollute oceans, warm our world and radically alter the biosphere, we are now influencing the evolution of all living things, near and far. Although these changes are not calculatedly deliberate, they are still post-natural because humans are at the helm. Our activities are placing the natural world in danger and now many wild species face an uncertain future. Extinction is now an everyday occurrence and even seemingly bulletproof populations of common species are taking a pummelling.

As the pace of environmental change intensifies, evolution is speeding up. Weird hybrids are appearing and new species are beginning to evolve. Polar bears and grizzly bears are giving birth to hybrid ‘pizzly’ offspring. Narwhals are mating with beluga whales. Mice in New York’s Central Park have evolved the ability to digest pizza, while anole lizards in Puerto Rico have evolved stickier toe pads that help them cling to buildings. Hunting is causing elephants to evolve smaller tusks, pollution is driving the emergence of toxin-resistant fish and climate change is causing birds to evolve new plumage.

The timing of these events is no coincidence. They are the repercussions of our actions. They may not be premeditated, but they are far-reaching. Now we live on a planet where humans have become the dominant force sculpting evolution. The world hasn’t seen evolutionary change on this scale since the demise of the dinosaurs. Life is changing. Humans are responsible.

The stories I share in this book are predominantly from the animal kingdom, although other walks of life are also available. This reflects my own mammalian bias, so apologies to the various groups that are under-represented. It is a book in three slightly overlapping parts. The first part describes the species we have engineered deliberately. It charts the rise of domestication, selective breeding and modern molecular methods to alter the DNA of living things. It describes our complicated relationship with the natural world and our growing sense of mastery over it. The second part describes some of the species whose evolutionary paths we have modified accidentally. It considers what happens when domestic species start to displace wild ones, and the evolutionary repercussions of humanity’s global reach. In the final part, we’ll explore some of the methods that are being used to restore the world’s lost biodiversity and guide evolution onto more secure footings. These stories are a source of inspiration and of hope, because they show us that, when humans take time to care about natural world, great things are possible.

CHAPTER ONE                                               

The Wolf that Rolled Over

Please don’t judge me. I am about to tell you something you may find shocking, and I am concerned you may think badly of me. When I’ve told people before, it has divided opinion. Some have been curious, others downright disgusted. They’ve told me it’s unnatural and asked me how I could do such a thing. I’ve no idea how you’ll react, so I’ll just come straight out and say it.

I own a genetically modified wolf.

I really do. My husband and I got him from a breeder that we found on the Internet. We exchanged a couple of emails, transferred a hefty wedge of cash then collected him from a pre-arranged location in southern England. The little animal howled all the way home.

Five years later, we now trust him so much that he lives in our house, sleeps on our bed and plays with our kids. If we were to set him free, I’m almost certain he wouldn’t survive. He’s never hunted fresh meat or brought down a caribou. He’d probably hang around by our back door, sulk and wait to be let back in again.

Higgs, as we call him, is a weird-looking wolf. His DNA has been altered so he is less than half the size of his free-roaming ancestors. His skull is smaller, his snout less pointy and his ears flop down rather than standing erect. The classic sleek pelt has been replaced with what can only be described as an embarrassment of soft, messy curls. He is black all over, except for his nose, belly, tail and feet, which are white … or brown when he’s been digging in the garden. His tail wags rhythmically when he hears the word ‘cheese’. Behaviourally, all trace of wolf cunning has been obliterated. The result is an animal so far removed from its original wild form that he barks at bin bags and often refuses to go out in the rain.

Before you pass judgement on this apparent lupine freak, let me tell you I am not the only one to own a genetically modified wolf. Millions of people, all over the world, keep similar animals but know them by a different name. They call them dogs. For dogs are genetically modified wolves.

When people think about genetic modification (GM), they tend to think about animals and plants whose DNA has been sculpted using the modern tools of genetics, but domesticated species have been genetically manipulated too. From the diminutive dachshund to the massive Saint Bernard, all dogs are descended from the European grey wolf. At some point in the past, humans and wolves crossed paths, and then somehow, somewhere, the wolf began to change. Its appearance altered. The wolf began to shrink. Its coat changed colour and its face changed shape. Physiological differences emerged, like the ability to digest starch and give birth more often. Its behaviour changed. The fearsome apex predator morphed from an animal that actively shuns human company into one, like Higgs, that demands it. All of these differences are underpinned by changes to the wolf’s genetic code. Now, although wolves and dogs still share around 99.5 per cent of their DNA, the tiny fraction that is different is enough to imbue them with their vastly different features.

Today, dogs have become such a normal part of our lives that it’s easy to take them for granted, but their emergence marks a defining moment in the natural history of our world. Dogs were the first domesticated animals. It was the first time humans took a species and then fashioned it to become something more preferable. It was the first time we wrestled control of evolution and began to steer the biology of living things in a different, post-natural direction. The emergence of dogs paved the way for other domesticated species to follow, triggering a chain of cause and effect that would change our world for ever.

According to the most recent estimates, modern humans evolved in Africa sometime between 350,000 and 260,000 years ago, and for the vast majority of the time that followed, we simply lived off the land. We existed as hunter-gatherers, and were entirely dependent on wild animals and plants for our survival. Domestication changed all that. Around 10,000 years ago, after we had domesticated dogs, we began to strike up alliances with other wild organisms. The repeated harvesting and sowing of wild cereals led to the creation of domestic crop strains that were more bountiful and easier to grow. We domesticated other animals, like sheep, cows and goats, and as we began to corral and keep them, and tend to our crops, we found ourselves increasingly tied to the land. The nomadic hunter-gatherer way of life gave way to a more settled existence, leading to the formation of villages. Because they could be bred, domestic animals provided a renewable source of meat and milk for food, and wool and leather for clothing. Food became more plentiful and the population began to grow. In time, because they could be owned and were easily trans­portable, domestic animals and plants went on to become a source of capital and wealth, so domestication fuelled the rise of trade. It drove the development of new technology, like ploughs, which further accelerated the rise of agriculture and in time led to the development of urban communities. When we think about key innovations, it’s all too easy to dwell on recent inventions like the Internet and antibiotics, but it’s no understatement to say that domestication helped to fuel the rise of civilisation, and changed the course of human history.

Looking around me now, I see a world full of domesticated species. My genetically modified hound, Higgs, slumbers peacefully at my feet. In the garden outside, our five chickens peck at corn, while our two rabbits nibble on a carrot. There are ponies in the field next door, and sitting on the fence post, a wayward tabby cat eyes me with disdain. Sitting at my desk sipping milky tea,¹ it’s hard to imagine a time when the world was not full of domesticated animals, plants and the products derived from them. Yet, for the vast majority of time that there has been life on Earth, there have been no domesticated animals or plants. So when and where did this momentous change take place?

What Was the Time Mr Wolf?

Until quite recently, scientists thought dogs were domesticated around 15,000 years ago, towards the end of the last Ice Age. It was a time when the ice sheets were retreating, when the landscape was newly green, and when humans and other animals began to colonise the northerly regions of Europe and Asia. There are plenty of dog fossils from this time, found in archaeo­logical sites across Europe, Asia and North America, and the scientists who have studied them all agree: these remains belong to dogs, not wolves. The proportions of their skulls and the shapes of their teeth are all quite different. But then came a fossil that left people scratching their heads.

The skull was discovered in the Goyet Cave in Belgium. It’s a remarkable archaeological site jam-packed with the bones of ancient humans, Ice Age animals and other captivating relics. ‘The skull is quite small,’ says Mietje Germonpré from the Royal Belgian Institute of Natural Sciences in Brussels, who studied the fossil. ‘It is about the same size as a modern German Shepherd skull.’ Wolves have long, slender snouts, but this animal had a shorter, wider muzzle and a broader braincase. It also had large, primitive-looking teeth. Collectively the features suggested that this animal was more dog than wolf. ‘So we decided it was a primitive dog,’ she says.

Then came the bombshell. Radiocarbon dating revealed that the skull was actually much older than previously thought. The creature was 36,000 years old, potentially pushing back the origins of domestication by a staggering 21,000 years. ‘We were very surprised when we found out,’ says Mietje. The skull divided opinion. Some people agreed with Mietje. Others did not. ‘They said it’s too old and they don’t consider it to be a dog,’ she says. Critics pointed out that wolf skulls from this time vary enormously in size and shape and suggested that the Goyet skull belonged to an odd-looking wolf rather than an early dog. Then a different group of researchers made a computer-generated 3D recon­struction of the skull and concluded that certain features, like the way the snout protruded from the skull, were also wolf-like. It could have been an end to the debate, but then other fossils cropped up. Mietje has studied dog-like skulls from the Czech Republic and Russia that are over 25,000 years old, while a separate research group has described the 33,000-year-old skull of a presumed dog found in Siberia’s Altai mountains. What to think?

It’s bound to be tricky. If these animals really are early dogs, then they’re ‘only just’ dogs so they’re bound to have dog- and wolf-like features. So it’s here that scientists are turning to another form of historical evidence to help resolve the conundrum: ancient DNA.

Although DNA breaks down after death, sometimes the molecule can be preserved inside fossils, and extracted and studied. This gives scientists another way of studying the transition from wolf to dog. In the early days, genetic analyses painted a confusing picture. One study, for example, compared the full genetic sequences, or genomes, of modern dogs and wolves, to determine that dogs were domesticated between 11,000 and 16,000 years ago. Another study of ancient canids, which focused on a subtype of DNA hidden in the cells’ energy-generating mitochondria, suggests a date between 19,000 and 32,000 years ago. The results present a massive discrepancy. On the one hand, they suggest dogs were domesticated around the end of the last Ice Age at a time when agriculture was emerging. On the other, it seems they were established on the other side of the Last Glacial Maximum, the time when the ice sheets were at their greatest reach.

The debate moved on in 2015 after Swedish researchers discovered a fragment of rib protruding from a Siberian riverbank. They originally thought the bone belonged to a reindeer, but DNA analysis later confirmed that it came from a wolf. Radiocarbon dating suggested that the animal died around 35,000 years ago, long before dogs were thought to be domesticated, but then further genetic tests muddied the waters. The ancient wolf seemed to be equally related to both modern domestic dogs and modern wolves, but how could this be if dogs had yet to evolve? The team concluded that the ancient wolf must have lived just after the split between the ancestors of today’s dogs and the ancestors of modern wolves. This means an earlier date of domestication, around 35,000 years ago, looks increasingly likely. Then in 2017, a different group of researchers arrived at a similar conclusion, this time using Neolithic dog fossils.

As more studies are added, an early date for the metamorphosis of wolves into dogs looks increasingly likely. Genetic analyses and fossil evidence hint at a deep connection between humans and dogs that stretches back much further than was initially assumed. It pre-dates the rise of agriculture and settled societies, and now researchers find themselves arguing over when and where the transition occurred.

Today, the grey wolf is the only member of the canid family to have paws in both the Old and New Worlds. Its current range encompasses much of Europe, Asia and North America, but in the past, its territory was even greater. This makes it hard to know where to start. We know that dogs cannot have been domesticated in North America, because humans didn’t arrive there until well after the Last Glacial Maximum when domestication was already well under way elsewhere, but that still leaves much of the globe to consider. Fossil finds point to Europe and further east to Siberia where the earliest, most primitive dog skulls have been found, but ancient DNA studies throw up alternative scenarios. Some suggest dogs became man’s best friend in East Asia, while others hint at origins in Central Asia or the Middle East. Meanwhile, a recent study that compared genetic material from modern and ancient specimens revealed an old, deep split between East Asian and Western Eurasian dogs. The most obvious explanation, according to the study’s author, Greger Larson from the University of Oxford, is that domestication occurred in at least two different places. The story of dogs may have no single origin. Dogs could have been domesticated multiple times in multiple places.

What intrigues me most, however, is how this relationship began. We can be pretty certain that our ancestors didn’t just wake up one day and declare they wanted something that would fetch a stick, yet the process of domestication had to begin somewhere.

Hounds of Love

The winter had been cold and long, but now the sun climbed higher in the sky and leaves were beginning to unfurl. The youngster sat on his haunches, staring into the embers of a fire that was dying down. He felt resentful. Not quite a boy, but not yet a man, he had been left behind in camp while the adults went out to search for food. Now he found himself alone, contemplating mischief.

A few days earlier he had followed his father out of the camp and into the woods. His father showed him a place where a large tree had fallen, wrenching deep-seated roots out of the rust-coloured earth, and the resultant hole that had been exposed in the hillside. Sharp-clawed paw prints framed the entrance to a dark tunnel: the unmistakable signature of a she-wolf’s den. ‘Be careful,’ his father had warned him. ‘These animals are dangerous.’

Back in camp, the boy knew he had hours before the hunting party would return, so he picked up a spear and slipped out of camp. He returned to the den to find fresh scats on the ground outside. The mother wolf had been there but when she heard his clumsy footsteps, she had beaten a swift retreat. Now she hovered in the background, watching as the human dropped to his knees and plunged his arm deep into the lair. When he stood back up, he was holding a small, wriggling wolf cub. It squirmed and whined, making the boy tighten his grip. Then he swaddled his find in a reindeer hide and carried it back to camp.

*  *  *

Although humans and wolves have shared the same landscape for many tens of thousands of years, they interacted little. Both would have been wary of the other and kept their distance, but then something must have changed. Academics argue over the nature of this initial interaction, but one scenario is that humans actively decided to invite the wolf into their world. Someone, like our Palaeolithic boy, went out and collected a cub. Skilled hunter-gatherers with an in-depth knowledge of their local environment, they would have known where the wolf dens were. It wouldn’t have been difficult to scoop one up and bring it back to camp. Then, having done it once, it would be all too easy to repeat the process. The cubs that were kept would inevitably have been the ones that were easiest to catch, so over time, as the genes for their more relaxed nature were passed through the generations, domestication got under way.

Back in camp, the animals would have been kept for pragmatic purposes. As cubs, they could have entertained the children. As adults, they could have acted as sentries, and if they ever got too boisterous or aggressive to look after, they could have been set free or killed for their meat and fur.

We certainly know that Palaeolithic people wore specialised cold-weather clothing, including a variety of fitted garments made from well-tanned pliable hides. A 24,000-year-old ivory figurine from southern Siberia, for example, depicts what seems to be an individual wearing a carefully tailored all-in-one fur suit. Evidence for a wolf-fur onesie? It’s a possibility. Similarly ancient wolf bones have been found with distinctive cut marks, indicating that the animals were probably skinned for their fur. They may also have held symbolic significance. One skull, studied by Mietje, is interesting because it has a bit of mammoth bone wedged between its front teeth. The fragment must have been inserted into the animal’s mouth after it died, suggesting human intervention, while other skulls sport conker-sized holes where their brains were removed. There were easier meals to be had than brain, so Mietje thinks these unusual relics are evidence that dogs held special significance. ‘I’m in favour of the active involvement of the Palaeolithic people,’ she says. ‘I think they actively started to collect these animals and then kept them, not just for their fur, but for rituals too.’

It is, perhaps, easiest to imagine that humans chose the wolf, and that the wolf had no option but to go along with our plans. As a species, we like to think we are superior and separate from the animal kingdom, when really we’re just animals too. Today, if we want a dog, we can just go out and get one, but it would be naive to presume that our ancestors followed the same thought process.

So an alternative theory proposes, not that humans chose wolves, but that wolves chose humans. Leftovers discarded by humans lured the wolves out of the shadows. The animals that were least afraid of us were the ones most likely to enter our campsites. As a result, they were better fed, healthier, and more likely to reproduce than warier pack members. The genes underpinning their more relaxed nature were passed between generations, and over time, the animals became progressively tamer. In this ‘self-domestication’ scenario, humans were stooges. We didn’t invite wolves in, but by being messy, we created an ecological niche they were only too happy to fill.

It’s a possibility. Modern wolves are adaptable animals. In Canada, there are two types of wolf: ‘nomadic’ wolves that follow the caribou around and ‘sedentary’ wolves that tend to stay in one place. From time to time, their paths cross, but they don’t really get on. They’re like the Starks and the Lannisters, and will fight each other to protect what they consider to be their caribou. So maybe, 35,000 years ago there were one or more groups of migratory wolves that considered us to be their property. Instead of tracking caribou or reindeer, they followed us around, not because they wanted to eat us but because they benefited from the shared association.

So which was it? Did humans choose wolves or did wolves choose humans? We’ll probably never know but the upshot was the same. After contact was made, humans and wolves began to interact and over time, the relationship strengthened. Primitive dogs probably accompanied humans on their hunts and so tipped the odds in favour of a kill – a reciprocal arrangement that benefited both parties. At some point, when we started to physically keep them with us, we would have started engineering which animals got to reproduce. In the early days, it would have been the calmer animals that would have tolerated living in captivity, but in later times we would have selected for other characteristics, like being a good sentry or scaring the neighbours. It was the beginning of a long and beautiful friendship, and a defining moment in the story of evolution. Of course, dogs were only the beginning …

Pigeon Parade

If Charles Darwin is to be remembered for only one book, it has to be the now classic On the Origin of Species by Means of Natural Selection. Published in 1859, this highly readable doorstop outlines the great man’s theory of evolution by natural selection. According to the theory, individual members of the same species are similar but slightly different. These variations make the individual more or less suited to the surrounding environment. The best adapted or ‘fittest’ individuals are more likely to reproduce and pass their winning characteristics on to future generations, while those less suited are more